From arstechnica.com:
YouTube was recently caught displaying ads that covertly leach off visitors' CPUs and electricity to generate digital currency on behalf of anonymous attackers, it was widely reported.
Word of the abusive ads started no later than Tuesday, as people took to social media sites to complain their antivirus programs were detecting cryptocurrency mining code when they visited YouTube. The warnings came even when people changed the browser they were using, and the warnings seemed to be limited to times when users were on YouTube.
And I do mean to resonate with Darwinism there.